Last time I went shopping for a child’s birthday gift, I was struck by how usual it seemed to be in a toy store the size of a big-box discount mart. When I was a child, the only real mega-size toy store in the world was Hamleys in London (still the world’s biggest!) For those of us not fortunate enough to live within pilgrimage range of Hamleys, the toy store was a small shop on the street, or a section in a department store. It has been many years now since I have seen a small toy store – I don’t even remember having seen a toy section in a department store recently. Come to think of it, since we have been back in the USA, I can’t remember having seen any toy stores at all except for the one big chain. I hope it’s my lack of attention and not an actual monopoly. The big retailer has a mind-boggling selection, more variety than I ever imagined as a child, but it just doesn’t feel like a toy store to me. Getting old, I guess.

I like the old toys, the ones I remember from childhood. The wooden train set, the LEGOs, the teddy bear. You know, the toys that have been around forever. Or have they? (Cue dramatic music.)

Of all the classic (or old-fashioned, depending on your point of view) pre-electronic toys, teddy bears are among the newest. They were first manufactured for sale in 1902 (LEGO goes back to 1934). There is no doubt that teddy bears had existed before 1902 – people have made stuffed toys for their own children for centuries, and dolls go back to the dawn of civilization – but nobody can verify dates for unique, home-made toys from hundreds of years ago, so toy history has to deal with factory-made toys available for sale to the public.

Of all toys, the teddy bear has the coolest legend behind its origin. President Theodore “Teddy” Roosevelt is usually credited with being the inspiration for the creation of the teddy bear. Unfortunately, this turns out to be not quite true. I can already hear the angry howls of outrage from Teddy Roosevelt fans everywhere. Slow down and give me another minute. The legend is true; it’s the connection to teddy bears that doesn’t quite hold water.

For those readers who don’t know what the fuss is about, the legend – which, I repeat, is completely true – goes like this:

President Teddy Roosevelt was an avid outdoorsman – a genuine tough guy who loved big-game hunting. His physical fortitude was matched by his strength of character, which fact explains his continuing stature in American history as one of our great leaders. In November of 1902, President Roosevelt was invited on a bear hunt by the governor of Mississippi. After a long, exhausting day of hunting, Roosevelt still had not bagged a bear. He may have been in a bad mood at that point – hard work with no results will do that to most of us – and some of the staffers hunting with him thought it would be a good idea to make sure the President got a bear. In the end, hunting guide Holt Collier, aged 56, went out and brought a large black bear back alive – an incredible feat for a single hunter before tranquilizer darts. The bear was exhausted and hurt; the staffers tied it to a tree, brought the President, and told him he could shoot the bear. To his credit, Teddy Roosevelt was disgusted. No self-respecting hunter would shoot an animal that way. He refused, to the surprise of lesser men present. People talked; the word spread. The ground was laid for the legend of the Teddy Bear.

On November 16, 1902, the Washington Post published a drawing by political cartoonist Clifford Berryman. The cartoon showed President Roosevelt refusing to shoot a captive bear. Most readers paid more attention to the picture than to the caption: “Drawing the Line in Mississippi.” Berryman was using the hunting incident as a metaphor for President Roosevelt’s attitude towards racism in the South (and Mississippi in particular). The President had openly criticized the Mississippi state government for failing to stop lynchings of black citizens. He had also made a friend of his hunting guide Holt Collier, which was only an issue because Collier was black. The icing on the cake, though, came when President Roosevelt invited Booker T. Washington to dinner at the White House. Washington, the great black orator, activist, and political advisor, had been at the White House before, but always on business. This was different; this was a social occasion. Racists were furious at such a public statement of race equality. Berryman’s cartoon was an acknowledgement of Theodore Roosevelt’s contribution to civil rights in America. But it was 1902; sixty years too early for civil rights. The cartoon inspired a Brooklyn shopkeeping couple, Rose and Morris Michtom, to make and sell small stuffed bears – called “Teddy bears”, of course. The toys became immensely popular almost overnight. Teddy bears became the most popular toys in the world; they still are today, after an 111-year run.

So where is the legend wrong? The problem is that, although President Teddy Roosevelt did indeed inspire the Michtoms to make toy bears, and although Berryman’s cartoon was directly responsible for the popularity of the teddy bear, the first factory-made teddy bears were made in Germany by Richard Steiff. There are at least two important facts supporting Steiff as the creator of the modern teddy bear, rather than Michtom:

First, Michtom’s toy bear was directly inspired by the Nov. 16, 1902 cartoon referring to the Roosevelt hunting incident. Even if the Michtoms could have gone from the idea stage to production of the first prototype bears, and sold them before Christmas, this places the origin of the toy bear in America at the very end of 1902. The Michtoms’ son Benjamin remembered a letter from February 1903 from his mother to the President, requesting permission to use the name “Teddy” to market the bears. This letter has never been produced, but it is reasonable to date the beginning of teddy bear production in America to the beginning of 1903.

Second, the Steiff factory did begin production of toy bears in 1902, although they were not called “teddy bears” until after the Michtom bears became popular by that name.

Third, the likelihood of Steiff producing toy bears before Michtom is increased by the fact that Steiff was an established toy factory that had been making stuffed animals since 1880. The bear was a new addition to a number of stuffed animal toys, the first of which was an elephant. The Michtoms’ business was stationery, not toys; the bears were made by Rose Michtom as a personal response to the Roosevelt hunting story.

So, although the legend of the Teddy Bear remains intact, it was responsible for the name and the popularity of the toy, not for the stuffed bear itself. It will always be a good story, and even more so if we remember the character and the values of the man who gave his name to a stuffed bear.

One of my pet peeves – which, unfortunately, will almost certainly never change – is our system of counting time.

The standard number system for everything else in the world is the decimal system, or base-10. Place value in the decimal system is ten times greater to the left and ten times less to the right. For example, “333” means three ones, three tens, and three hundreds; “3.33” means three ones, three tenths, and three hundredths. Since five is half of ten, one half is written “0.5”. One fourth (half of one half) is “0.25”. Anyone who can read a price tag at the store can use the decimal system. It is beautifully simple to use; if you think I am exaggerating, try doing some long division with Roman numerals, or add up some groceries in binary (if you really enjoy suffering, use hexadecimal).

The decimal system is great. So why don’t we use it to measure time? An hour and a half is 1.5 hours, but when we write it in hours and minutes, it comes out 1:30 instead. This makes it difficult to calculate the cost of something per hour, because minutes are sixtieths of an hour instead of hundredths. If I rent a boat for $6.50 per hour, and I want it for three hours and fifteen minutes, I might try to multiply 6.5 times 3.15; I will end up owing money. Three hours and fifteen minutes equals 3.25 hours, not 3.15.

Here’s a simpler example. Imagine that I pay my son minimum wage – $7.25 per hour – to mow the lawn. When he finishes, the timer reads 0:35, or 35 minutes. To pay him, I have to divide $7.25 by 60 and multiply by 35. This is no fun.

What if there were 100 minutes in an hour instead of 60? Then I could just multiply $7.25 by 0.35 – a single operation instead of two.

If we divided the day (from sunrise to sunrise, or midnight to midnight) into 10 hours, each hour into 100 minutes, and each minute into 100 seconds, our timekeeping would be much easier. Of course, the minutes and seconds would be a little longer than they are now, but not that much. It would be far easier to teach children to tell time without all the twelves and sixties. Everything would be better!

So how did our clock get messed up? Why do we use a 12-base clock when everything else is 10-base?

The answer goes all the way back to the beginning of clocks. The first clocks we know of were sundials in ancient Egypt. Sundials are great when the sun is shining, but less so when it is cloudy, and not at all during the night. Ancient Egyptians divided the daylight into ten hours (sensible people!) but added a twilight hour at the beginning and another at the end of the day. Since their sundials did not work at night, this gave them twelve hours. Much later, after inventing ways to keep time during the night, people doubled the daylight hours for the nighttime. From sunrise one day until sunrise the next day, there were 24 hours (and still are today).

The number 12 works well with another number system, 60-base, which was used by ancient Babylonians (who were very good astronomers despite having a horribly clunky number system). The ancient people of India and Sri Lanka were also great astronomers and used 60-base systems; our word “hour” comes from the Indic word “hora”.

No matter how good ancient people were at astronomy, I think we would be better off with a decimal time system. But that is not likely to happen, because all the systems used all over the world by 7 billion people use the 12-base clock. Oh well!

Black holes are definitely some of the most mysterious things in the universe. A hole that looks the same from all sides is quite a puzzle!

If I were to go up into the attic and saw a circular hole around me, I would fall down into the living room. Likewise, if there were a hole in my living room floor, I might keep falling down into the basement. This is easy to imagine. It is not too much harder to picture gravity reversing, so that I would fall up from the basement through the hole in the living room floor, ending up back on the couch where I started. In each of the three places I had been – the living room, the attic, and the basement – I could look through (or fall through) a hole to another space.

Before I start talking about black holes, I should say that everything we know about them is based on math. Until 1971, there was no observed evidence that they even existed. Today, there are many known black holes, but we will never see one of them directly, so all our knowledge of black holes is based on measurements of things happening in space that cannot be explained without the math model of a black hole. Most of my readers are not math professors, so you may be wondering what I mean by “math model”. If I tell you that I am thinking of an object that is 5 cm long, 5 cm wide, and 5 cm tall, you could guess that it is a cube. But what if it is a sphere? All you really know is how big it is. Now, if I tell you that the object has six square sides, you know it is a cube. You can picture it in your mind. There is no real cube, but your image of it is based on numbers I gave you. The cube in your mind is a math model.

Remember the holes in my ceiling and floor? Now imagine a hole in the middle of empty space. It is not a hole in a wall or anything else; it is a hole in space. You might be able to see the hole if you got close enough, but you would not be able to see through it. If you moved in a big circle around the hole, it would look the same from any angle! If you were to throw an object – like a marshmallow – through a hole in a wall, you could look over the wall (or through the hole) and see the marshmallow on the other side. But if you threw a marshmallow into a black hole, there is no other side. It is gone forever!

How can this be? About 250 years ago, a scientist named John Michell imagined a thing nobody had thought of before.

(Scientists of his time already knew that objects had to reach a certain speed to escape the gravity of any planet or star; this speed is called the “escape velocity”. The more massive a planet or star is, the faster an object has to move to escape out into space. This is why a rocket can get to the moon, but a bullet from a gun cannot. It is not fast enough. A rocket fast enough to escape the Earth’s gravity would still not be able to escape the Sun, because the Sun is so much more massive than the Earth. You would need a much faster rocket. On the other hand, if you have seen pictures of the Apollo missions to the Moon, the rocket they used to get off the Moon was not very fast at all. It didn’t have to be; the Moon is much less massive than the Earth, so its gravity is much weaker.)

John Michell imagined a star so massive that even light would not have enough speed to escape its gravity. If the light from the star could not escape out into space, then nobody would be able to see it! John Michell called his imaginary star a “dark star”. Later scientists, including Albert Einstein and Karl Schwarzschild, made math models of dark stars to describe the behavior of light and of objects that got close to them. It was a scary but fascinating idea! In 1964, a journalist named Ann Ewing wrote a report about these math models. The report was called “Black Holes In Space”. Since then, people have been calling them “black holes”.

Even though many scientists made lots of math models of black holes, nobody had ever seen one. They are, after all, invisible! Between 1971 and 1973, a team of astronomers watched a giant star far out in space. It behaved unlike any other star. By 1973, they knew from their measurements that the star had a black hole next to it, just like you knew (after getting enough information) that the object I was describing was a cube. The star system fit the math model: it could only be a black hole!

That first observed black hole is called Cygnus X-1. Since then, we have observed many other black holes. Although they are invisible, we know they are black holes from observing what happens around them. If it fits the math model, it must be a black hole.

So what is the answer to the question we started with? If you fell into a black hole, where would you go? By now, you know that black holes are not really holes at all. They are objects with such strong gravity that nothing, not even light, can escape them, which is why they are perfectly dark. Because its gravity is so strong, anything that falls into a black hole is crushed into zero volume. Since one of the properties of matter is that it takes up space, objects falling into a black hole would really not even be objects anymore. The center of a black hole is called a “singularity”, and the math model for a singularity seems to break the rules for what we know about the universe.

There is a beautiful park a couple of blocks from my house. Groves of big shady trees line the shores of the lake; the footpath winds through the trees, over bridges and around an open field perfect for flying kites. It is a nice place to go for a walk, or a bicycle ride, although the summer here is too hot to be outdoors except early in the morning or after sundown.

Yesterday we rose early and rode our bicycles down to the park. The air was still cool in the shade, but the sun was up and it would be hot before long. As we turned onto the path, I spotted a large turtle, a red-eared slider, in the grass near the path. It was a good fifteen meters from the water, which was strange; when the turtles pull themselves up onto the bank to bask in the sun, they usually stay right at the water’s edge, ready to slide back into the lake at the first sign of someone approaching. Why was this turtle so far from the safety of its habitat?

I stopped and signaled the boys to come slowly and quietly. As we watched, the red-eared slider dug into the ground with its hind legs and began laying a clutch of eggs! Slowly it began to scrape the soil back into the hole to cover them up.

Turtles, like all reptiles, are exothermic (or “cold-blooded”); they depend on the environment to warm or cool their bodies. If a turtle lying on the shore gets too hot, it goes back into the water to cool its body. But this turtle was a long way from the water (at least, for a turtle!) As I watched the turtle covering its eggs, I began to worry that it would overheat. The spot it had picked to dig its nest had been in the shade when it began digging, but now the sun beat down directly on the turtle’s shell. I wondered how long it would take for the turtle to finish covering its eggs and drag itself back down to the lake.

I need not have worried. A few minutes later, the nest covered and nearly invisible, Mother Red-Ear was on her way back to the cool water. She stopped in the shade of a hackberry tree to rest beside a fallen branch. Soon she was back in the water.

Andres asked, “When the baby turtles hatch, how will they find the lake? What if they go up onto the road instead, or get lost in the park?”

The short answer is that aquatic turtles hatch with the instinct to go straight for the water. They don’t know where the water is, or even what it is; they have no experience at all, yet they all head for the water as quickly as a baby turtle can (which is quite a bit faster than the adults, on land anyway). Instinct drives them; they can’t help it. The reason for this instinct is obvious: the ones, long ago, who went in any direction other than the water failed to survive, and never grew up to pass that trait on to their offspring. Today, all aquatic turtles are descended from turtles who survived by seeking the water as soon as they hatched, and so all aquatic turtles have that instinct.

So turtles go to water because of survival instinct. But what makes a hatchling turtle move in the right direction? There must be something a baby turtle can sense in order to trigger the instinct. Since gravity makes water lie in the lowest part of any area, it makes sense to think that newly hatched turtles would follow the slope of a beach or lakeshore down to the water. Another possibility is that the mother turtle leaves a scent trail for the hatchlings to follow, but since the eggs take two to three months to hatch, it seems unlikely that there would be much of a scent left to detect. Finally, researchers have observed that baby sea turtles can become confused by electric lights near the beach, becoming attracted to the lights instead of the water. On a beach with no electric lights, the brightest place is the water because it reflects moonlight or starlight from the sky. Maybe turtle hatchlings find their way by the difference in brightness between land and water.

Our turtle’s eggs should hatch towards the end of summer. We will be watching for the baby turtles to crawl down to the lake. One way or another, they will find the way!